GASTEROPODA. 69 



M. Testa turbinato-conicd, leevi; spird elatd, obtusd; anfractibus planis seu subconvexis; 

 suturis vix impressis; anfrdctu ultimo permagno; aperturd ovatd; umbilico nutto. jEtate 

 adultd testa elatiore. 



Shell turbinated, conical, oblique, smooth ; spire elevated, obtuse ; whorls flattened, or 

 slightly convex, the sutures rather indistinct ; the last whorl very large ; the aperture ovate, 

 and the base without umbilicus or sulcus. 



The young shells are rather discoidal, but with increase of growth gradually become 

 obliquely conical, so much so, that the two extremes of the figure would scarcely be taken 

 for the same species. 



Locality. It is abundant in all the shelly beds of the Great Oolite formation near 

 Minchinhampton. Eparcy, France. 



SOLARIUM, Lam. 1801. 

 OMALAXIS. BIFRONTIA, Deshayes. 



Shell depressed, conical, or discoidal ; base concave, or widely umbilicated, the spiral 

 margin of which is angulated and crenulated ; aperture trapezoidal, with a thin peritreme. 



SOLARIUM POLYGONIUM, Archiac. Plate IX, figs. 24, 24#, b. 



SOLARIUM POLYGONIUM, Archiac. 1843. Mem. Soc. Geol. de France, torn, v, p. 378, 



pi. 29, fig. 1. 



Bronn. 1848. Index Palaeont., p. 1152. 

 D'Orb. 1850. Prod. Parent., p. 300. 



S. Testa discoided, spird parvd, anfractibus (4) planis, ultimo carinato ; angulis (9) 

 costatis ; costis elatioribus ; lineis transversis et longitudinalibus decussatis ; carind parvd, 

 nodulosd prope suturam sitd. 



Shell discoidal, spire small, whorls (4) flattened, the last whorl carinated and angulated ; 

 angles (9) costated ; costse elevated ; there are also encircling lines decussated by others 

 which are longitudinal, and a small, closely nodulated carina, surrounding the upper portion 

 of the whorls, near to the suture ; the first two volutions are smooth, rounded, elevated, 

 but minute. 



Locality. This species occurs in the vicinity of Minchinhampton more frequently than 

 any other of the genus, but, owing to its thinness and delicacy, few examples are well 

 preserved. The white stone of Bussage is the most favorable position for obtaining it. 



Great Oolite, Eparcy, France (D' Arcldac). 



SOLARIUM VARICOSUM. Plate IX, figs. 23, 23, b. 



S. Testa conico-depressd ; anfractibus (4) angulatis, lineis crebris transversis et lonai- 



10 



